1. Field of the Invention
The present invention relates to animal control devices. More particularly, the invention relates to a GPS-based apparatus for restricting the movement of animals which includes a collar device with a location determining component and an ear device adapted to deliver a corrective stimulus.
2. Description of Prior Art
Animal owners often desire to remotely or automatically control the behavior of an animal, either as a training method or as part of a containment system. For example, farmers often wish to contain livestock in a particular area and prevent the livestock from approaching and entering other areas. One well-known method of remotely controlling the behavior of an animal is by delivering a stimulus to the animal when the animal's behavior deviates from a desired pattern of behavior. An example of a device which delivers such a stimulus is an animal collar adapted to deliver an electrical shock or an acoustical stimulus to the animal.
Use of such collars as part of a containment system may be automated by including a Global Positioning System (GPS) receiver and memory element thereon. The memory element is adapted to store map or location information relating to a boundary or a restricted area. Such collars are adapted to determine a location by using information from the GPS receiver and the map or location information. If the animal wearing the collar approaches or enters a restricted area, the collar delivers a corrective stimulus, such as an electrical shock or an acoustical stimulus, thus motivating the animal to leave the restricted area.
These GPS-based control devices often include a GPS receiver and associated hardware; a computing means, such as a processor; memory hardware to implement the memory element; and a power source capable of providing power to the various other components of the device for extended periods of time. The combined weight of these components can dictate the location and manner in which the device can be attached to the animal. Furthermore, the GPS receiver requires a clear view of the sky in order to properly receive GPS signals from the orbiting GPS satellites. Thus, GPS-based control devices have been largely limited to collars, which places the weight of the device where the animal can tolerate it and gives the GPS receiver an adequate view of the sky necessary for effective GPS reception.
While a collar is adequate to support the GPS device, it does not place the device in an optimal position to deliver the stimulus. The acoustical stimulus, for example, may originate several feet from the animal's ear, significantly limiting its effectiveness. Furthermore, probes mounted on a collar to deliver an electrical stimulus, such as an electrical shock, may not make good contact with the animal's skin, limiting the intensity of the stimulus. Even if the probes make good contact with the skin on the animal's neck, that skin may not be sufficiently sensitive to the shock for the stimulus to be effective. Finally, probes located on a collar may cause irritation or injury to the animal's skin, especially if the probes frequently rub the skin as a result of collar movement. For these reasons it is desirable to locate the stimulator portion of the GPS-based control device in another location on the animal, preferably a location where the stimuli will have the greatest effect without causing the animal unwanted irritation or injury. One such location is the animal's ear. Ear tags are commonly used on cattle for identification, and could be adopted for use as stimulators. Unfortunately, however, an animal's ear is not strong enough to support the weight of the entire GPS-based device.
Another disadvantage of current control devices is that they require a user to place a collar on each animal the user wishes to control. Because GPS devices are expensive, a system that requires a collar on each animal is very costly.
Due to the above-mentioned and other problems and disadvantages in the art, a need exists for an improved apparatus capable of automatically, efficiently, and effectively delivering a corrective stimulus to a group of animals when the animals enter a restricted area.